Fur stretching and nailing machine



M c ,193 s. FRIEDMAN mm ,STRE'ICHING AN NAILING momma "Filed July 26, 192 5 Sheets-Sheet, 1

ATTORNEYS March 31, 1931. s. FRIEDMAN 1,798,664

FUR STRETCHING AND NAILING MACHINE I Filed Ju1y26, 1926 -s Sheets-Sfwat. 2

ATTORNEYS WITNESSES March 31, 1931. 5 FRjEDMAN 1,798,664

FUR STRETCHING AND NAILING MACHINE Filed July 26, 1926 3 Sheets-Sheet, 5

WITNESSES INVENTOR ATTORNEYS Patented Mar. 3 1, 1831 SAMUEL FRIEDMAN, OF BROOKLYN, NEW YORK FUR STRETCHING AND NAILING IVIACHINE Application filed July 26, 1926.

My invention relates to the stretching and nailing'of furs to be used for the making of coats and other garments. The usual fur or skin is stretched manually after being gripped 5 by a pliers. In practice, an Outline of the coat pattern or other garment is usually chalked on a table or board and the fur is stretched to correspond with the coat pattern and then nailed.

The general object of my invention is to provide a novel portable device for effecting the stretching of the fur and effecting the nailing of the same conforming to the outline of the pattern. 15 A particular object of the present invention is to produce a manually operable device for the indicated purpose in which the nailing hammer and other parts are completely operable manually and optionally manipulated in proper sequence. v

The nature of the present invention and its distinguishing features and advantages will clearly'appear as the description proceeds. 7

Reference is to be had to the accompanying drawings forming a part of this specification, it being understood that the drawings are merely illustrative of one example of the invention. V Figure 1 is a side elevation of a fur stretching and nailing machine embodying the present invention;

Figure 2 is a section on the line 22, Figure 7 4, and showin the hammer raised and held against operative movement;

Figure 3 is a view similar toFigure 2 but showing the parts with the hammer inthe position assumed after having delivered a blow on a nail or other fastener;

Figure a is a horizontal section as indicated by the line l-l, Figure 2; j V I Figure 5 is a transverse vertical section as indicated by the line 55, Figure 2;

Figure 6 is a fragmentaryview in vertical section illustrating a ratchet and pawl for adjustably holding the fixed hammer shaft against turning;

Figure 7 is a horizontal section on the line 7-7 Figure 2; the hammer being shown in 59 plan view;

Serial No. 125,019.

Figure 8 is a section on the line 88, Figure 7; V

Figure 9 is a diagrammatic View given to afford an understanding of the means or features functioning for the restoring ofthe 5 hammer to the raised position; 7 I

Figure 10 is a front end view of the device;

Figure 11 is a diagrammatic plan view of a piece of fur and indicating fasteners securing the same to a board or table. 69

In carrying out my invention in accordance with the illustrated example asuitable casing 15 is provided to house and support the variousparts of the mechanism, the said casing and the various parts of the mechanism being portable and being adapted to be carried about and manipulated by one hand of an operative, as will become clearer here+ inafter. On the casing 15 at the back thereof is a rigid handle 16 extending downwardly from the top of the casing to serve in manipulating the device. A fixed jaw 17 is formed on casing 15v at the bottom and above the same is a jaw 18 pivoted as'at 118. i The jaw 18 is rocked to draw its gripping end downward for gripping a piece, of fur A (Figures 3 and 11) by a slide 19mhaving a roller 20 contacting with the under side of the heel 218 of said jaw 18. The slide 19extends through a hole 21 in the back of casing 15. Said slide 19 is operated by a hanger lever 22 pivoted atits upper end as at 122 to handle 16 and extending downwardly in front of the vsaid handle, the lower end of said lever 22 having a forward extension 222 pivoted as at 24c to the adjacent end ofslide 19. The jaw 18 is adapted to be raised by a suitable spring 25 beneath the same. The lever 22 is so arranged relatively to the handle 16 as to permit both the lever and handle to be gripped by the hand of the operative in carrying and manipulating theportable apparatus.

The numeral 26 indicates the driving means in the form of a hammer head supported on arms 126, said hammer being loosely mounted on shaft 27 passing through the lower ends of arms 126. The shaft 27 has a ratchet wheel 28 (see Figures 5 and 6) keyed thereon and said ratchet wheel is adapted to be engaged by a pawl 29 having teeth 31, 32 approximately diametrically opposite. Said pawl 29 has also a finger piece 30 extending outwardly through casing 15 for rocking the pawl and thereby turning the shaft to the extent of one or more teeth on the ratchet wheel 28 for adjusting the tension of a spring 33. Said spring 33 is fast one end to normally fixed shaft 27 and is secured at its other end to a bar 34, in the form of a screw bolt, secured to the hammer arms 126 and loosely passing through an element 35 which functions in restoring the element 26 to the raised position and simultaneously stressing spring 33.

For lifting hammer 26 through the medium of element 35 thereon, a turnable element 36 has its hub 37 loosely mounted on shaft 27 said turnable element 36 being here shown as a worm wheel in mesh with a worm 38 on a drive shaft 39 actuated in any suitable man ner preferably through the medium; of a flexible driving shaft 40. V i

The worm wheel 36 has a stud 41 at the inner face thereof which is adapted in the turning of wheel 36 to engage intermittently a pin 42 on lifting element 35 of hammer 26, said pin 42 being on the heel 43 of element 35. A shoulder 44 is formed on heel 43 of element 35 and is adapted to engage a bevelled surface 45 on trip member 46, said trip member being in the form of a screw being ad justable to vary the time of contact of shoulder 44 with said bevelled surface 45. The timing of the contact has regard for the functioning of stud 41 in contact with the pin 42, so that said stud 41 will cam itself free of the pin 42 when the hammer approaches the raised position shown in dotted lines in Figure 9 and in full lines in Figure 2.

' For latching the hammer 26 and holding it in the raised position against the tension of spring 33, a pin 47 is provided on a side of said hammer adapted to be engaged by the head 48 of a latch 49 pivoted as at; 50 to thumb lever 51 fulcrumed as at 52 on the inner face of casing 15 at a side thereof.

Spring 53, Figures 2 and 3, bears against latch 49 and allows said latch to have a limitedyieldingrelatively to lever 51 while the latch is snapping into engagement with the pin 47 of hammer 26 and the head 48- of latch 49. At the opposite side of latch49 from said latch head 48, is a straight surface 54 adapted to bear flat against the adjacent shoulder 55 formed on thumb lever 51 to limit the downward movement of latch 49 under the pressure of spring 53. Hence, while the latch can yield upwardly, it is arrested in its downward movement by the contact of the flat surface 54 with shoulder 55. V

A vertical pin 56 is provided having a coil spring 57 thereon which bears at its lower end against a bracket- 115 on the casing 15 at the interior and at its upper end against a stud 156 on pin 56. The upper end of said pin 56 bears against the lower edge of the lever 51, the spring 57 tending to lift said pin 56 and maintain it in contact with lever 51. The lower end of pin 56 is adapted to enter a pin hole 58 in slide 19 when said slide is drawn rearwardly to a position closing the movable jaw 18.

I have indicated diagrammatically in Figure 11 a piece of fur A held at the edge by fasteners a to a board or table B, a fragment of which is indicated, said fasteners a being indicated as nails as usually employed. I have shown a preferred fastener 59 employed by me, the same being forked at its lower end and having a headed shank 159. The fasteners 59 are received in single succession in a slot 215 in casing 15 from a flexible tube C leading from nail feed devices (not shown) and not forming part of the present invention.

A nail release device 60 is provided, pivoted as at 160 to casing 15 below the slot 215 to rock in a vertical plane. Said release device 60 is formed with an upper point 61 and a lower point 62 as well as with a resilient finger 63 at the back of said device 60. The finger 63 is adapted to be struck by the hammer 56 as the latter is moved upward from the nail driving position by which action the lower point 62 of device 60 is withdrawn from beneath the uppermost fastener 59 to release said fastener and simultaneously with the release of'the fastener, the upper point 61 is projected inwardly above the falling fastener to hold the next arriving fastener. -As seen best in Figure 4 the lower fixed jaw 17 has a pair of slots 64 and the upper jaw 18 has a central opening 65. The slots 64 and opening 65 afford clearance for the tines-of the forked fastener 59 and for the shank 159 thereof in withdrawing the fur-stretching and nailing device rearwardly from engagement with a driven fastener.

At that end a shaft 27 remote from the squared end for receiving a key, I provide on said shaft a nail-pulling device 66 to remove the fasteners 59 or ordinary nails if the latter are employed. Said nail puller 66 has an internally threaded hub 67 screwed to the hub 37 of worm wheel 36 so that with the turning of worm wheel 36, the nail pulling device 66 will be revolved. Also, radial or approximately radial lugs 68 in'pairs are formed on the pulling device 66 and defining a slot 69 to accommodate the shank of the nail or other fastener. V

The numeral 70 indicates a stop to limit the downward movement of the hammer lifting element 35, (see Figures 2, 3 and 9). p

In the use of the device the jaw 18 being raised as in Figures 1 and 2, the edge of the piece of fur A is entered beneath said jaw. The jaw 17 is'entered beneath said jaw by graspingthe handle 16 and moving the dedriven.

vice forwardlyto position the fur A as shown in Figure 3, so that upon the aw 18 lowering onto said piece of fur, the fur piece A having been positioned as in Figure 3, the fingers are closed to draw the hanger lever 22 against the front of handle 16, whereby the slide 19 will be moved rearwardly and the roller 23 will engage the inclined under surface of the heel of jaw 18, thereby tilting said heel upwardly and causing the gripping end of jaw 18 to move doavnwardly toward the position shown in Figure 3. Vith the lever 22 against the handle 16 the hole 58 will have been brought into line with pin 56. Said pin 56 will, however, be maintained in the raised position by the spring 57 until the thumb lever 51 is depressed to move the pin 56 downwardly and the thumb lever at thesame time raising the latch 49 out of engagement with the stud 47 on the hammer 26. Thus, after the fur A has been gripped the hammer will drive a positioned fastener 59 through the fur and into the board or table B, Figure 11.

Before each stroke of the hammer 26 to drive a fastener, a fastener 59 will be positioned beneath the hammer as in Figure 3, this being permitted by the slots 64 and opening in the respective jaws 17 and 18. In the upward movement of the hammer, said hammer will engage the end of the resilient finger 63, thereby rocking the control element 60 so that the point 62 is withdrawn from beneath a fastener 59 and the point 61 is projected forwardly beneath the next fastener to hold the same and cause the fasteners to be fed in single succession as fast as one is The complete device is then withdrawn from engagement with the driven fastener. When a fastener 59 has been driven to a depth indicated in Figure 3, the spring 23 is permitted to throw lever 22 forwardly, thereby moving the slide 19 forwardly and thus causing roller 20 to move along the inclined lower edg'e at the heel 218 of jaw'18 permitting spring 25 to raise said aw and release the fur. The element-35 functions as follows the impact of the hammer 26 in driving fastener 59' causes the element 35 to contact with the pin 7 O wnich rocks said element 35 about the axis of its pivot, and this brings the pin 42 into the path of movement of the stud 41 to lift the hammer.

It is to be noted thatthe worm wheel 36 is constantly driven by worm 38. As the said wheel 36 revolves, it intermittently causes stud 41 thereon to engage the pin 42 on lift element 35, thereby lifting said element 35 and with it the hammer 26, to the arms 126 of which said element 35 is fastened by screw bolt 34. So long as the stud 41 and pin 42 are engaged, the hammer 26 will continue to rise. As the hammer approaches the completely raised position, the shoulder 44 on'element 35 will contact with the bevelled end 45 of screw 46. The element 35 is free to have a slight movement relatively to hammer 26 so that after contact of shoulder 44 with the bevelled end 45, the element 35 will be rocked on the hammer arms 126 and the hammer will complete its movement to the upper position until the stud 47 is engaged by the latch head 48 which snaps into engagement with the latch 49 because of the yielding spring 53. Finally, as the stud 47 is engaged by latch 49, the stud 41 will disengage the pin 42and permit the worm wheel 36 to revolve freely thereafter because the pin 42 will have been carried out of the circular path of movement of stud 41.

The raising of the hammer 26 will have stressed the spring 33 so that its re-action will throw the hammer downward for driving the fastener 59 when the hammer is released from latch 49 by the depression of thumb lever 41.

The numeral indicates a stop against which the upper end of element 60 contacts to prevent movement of said element by the hammer in a downward movement of the latter so that the hammer head can slip by the yielding finger 63 without movement of element 60. The numeral indicates a plate spring on the jaw 18 to engage fastener 59 so that the fastener will not drop down loosely, but will beheld in a position to be struck by the hammer 26.

I would state furthermore that whilethe illustrated example constitutes a practical embodiment of my invention, I do not limit myself strictly to the exact details herein illustrated, since, manifestly, the same can be considerably varied without departure fromithe spirit of the invention. Having thus described my invention, I claim: 1 I s 1. In a fur-stretching and nailing device, a pair of jaws adapted to grip an edge of a piece of fur, a manually operable slide engageable with one of said jaws to move the same to the gripping position, means to autom atically restore the j aw after a closing move ment, a hammer pivotally mounted, means to direct a fur fastener to a position to be struck by the hammer, latching means to hold the hammer in the raised position, a manually operable device to release the latching means, and means to prevent the operation of the latch releasing means until the slide has moved to a predetermined'position in the closing of the movable jaw.

2. In a fur-stretching and nailing device, a pair of jaws adapted to grip an edge of a piece of fur, a manually operable slide engageable with one of said jaws to move the same to the gripping posit-ion, means toautomatically restore the jaw after a closing movement, hammer pivotally mounted, means to direct a fur fastener to a position to be struck by the hammer, latching means to hold the hammer in the raised position, a

manually operable device to release the latching means, and means to prevent the operation of the latch releasing means until the slide has moved to a predetermined position in the closing of the movable aw; together with a fixed handle on said device, and a hanger lever at the front of said handle to be gripped by the fingers of a hand grasping the handle, and means pivotally connecting said hanger lever with said slide;

5. in a fur-stretching and nailing device, means to grip a piece of fur, a hammer to drive a fastenerinto the fur, latch means for the hammer, manually operable means to cause said gripping means to grip the fur, and optionally operable means to release the latch means; together with means to prevent the operation of the latch-releasing means until said operating means for the gripping means has functioned.

4:. In a device of the class described, apair of jaws one of which is pivoted to rock relatively to the other, said pivoted jaw presenting an inclined surface at that end opposite the gripping end of the pivoted jaw, a slide carrying an element engageable with said inclined surface, manually controlled means to operate said slide, a hammer pivoted to rock in a vertical plane, hammer latching means, and manually controlled latch releasing means.

5. In a device of the class described, a pair of a-ws one of which is pivoted to rock relatively to the other, a slide carrying an ele ment engageable with said pivoted jaw at the opposite end from the gripping end, manually controlled means to operate said slide, a hammer pivoted to rock in a vertical plane, hammer-latching means, and manually con-' trolled latch-releasing means. 7

6. In a device of the class described, a pair of jaws one of which is pivoted to rock relatively to the other, .a slide carrying an element engageable with said pivoted jaw at the opposite end from the gripping end, manually controlled means to operate said slide, a hammer pivoted to rock in a vertical plane, hammer-latching means, and'manually controlled latch-releasing means; together with a spring-pressed pin bearing against the latch-releasing means to be moved by said latch-releasing means, said slide having a hole into which the said pin may enter when the slide is in position after moving the pivoted jaw. I I

7. A portable article gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative and manually controllable arti: cle gripping and nailing mechanism all car ried by said support, said mechanism com prising article gripping means, said gripping means consisting of a pair of jaws, one of the jaws forming a supporting base for said device, manually operable means for actuating said gripping means, a driving means to drive a fastener into the gripped article, motor operated means for said driving means, said motor operated means in cluding a rotor element carried by the portable support andconnectible by a flexible drive shaft to an external power source, manually manipulab-le means for controlling the operation of said driving means, and a flexible nail feeding means connected to said support. a

8. A portable article gripping and nailing device comprising, a portable casing adapted to be carried about and maniplated by an operative, a handle for said casing and manually controllable article gripping and nailing mechanism all carried by said casing, said mechanism comprising article gripping means, said gripping means consisting of a pair of jaws, one of the jaws forming a supporting base for said device, manually operable means having a part arranged to be gripped with said handle by the operative for actuating said gripping means, a nailing means to drive a nail into the gripped article, motor operated means for said nailing means, said motor operated means including a rotor element carried by the portable casing and connectible by 'a flexible drive shaft to an external power source, manually manipulable means for con trolling the operation of said nailing means, and a flexible nail feeding means connected to said casin 9. A portable article gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative, a flexible nail feeding means connected to said support, a handle on said support for said hand of the operative, and

manually controllable article gripping and nailing mechanism all carried by said support, said mechanism comprising article gripping means, said gripping means consisting of a pair of jaws, one of the jaws forming a supporting base for said device, manually operable means having a part arranged to be gripped with said handle by the operative for actuating said gripping means, a driving means to drive a fastener into the gripped article, motor operated means for said driving means, said motor operated means including a rotor element carried by the portablesupport and connectible by a flexible drive shaft to an external power source, and manually manipulable means for controlling the operation of said driving means, said manually manipulable means being arranged on said support adjacent said handle and within manipulating reach of a finger of said hand of the operative.

10. A portable article gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by one hand of an operative and manually con- 4o hammer to drive a fastener into the gripped hammer, means for latching the hammer in trollable article gripping and nailing mechanism all carried by said support, said mechanism comprising article gripping jaws, manually operable means for operating said jaws, a hammer to drive a fastener into the article ripped by said aws, motor operated means for elevating said hammer, means for latching the same in an elevated position, and manuallyoperable means for unlatching said hammer to release the same for movement to fastener drivin position.

11. A portab e article gripping and nailing device comprisin a portable casing adapted to be carried a out and manipulated by one hand of an operative, a handle for said casing and manually controllable article gripping and nailing mechanism all carried y said casing, said mechanism comprising article gripping jaws, manually operable means having a part arranged to be gripped with said handle by the operative for actuating said jaws, a hammer to drive a fastener into the article gripped by said jaws, motor operated means for elevating said hammer, means for latching the hammer in an elevated position, and manually operable means for unlatching said hammer to release the same for movement to fastener driving position, said manually operable means being arranged adjacent said handle for manipula tion by a finger of said hand of the opera tive.

12. A portable article gripping and nailing device comprisin a portable support adapted to be carried a out and manipulated by an operative and manually controllable article ripping and nailing mechanism all carried by said support, said mechanism comprising article gripping means, manually operable means for actuating said gripping means, a

article, means for elevating said hammer and for latching the same in an elevated position, manually manipulable means for unlatching said hammer to release the same for movement to fastener driving position, a flexible 'i carried by said support, said mechanism comprising article gripping means, manually operable means for actuating said gripping means, a hammer to drive a fastener into the gripped article, means for elevating said an elevated position, and manually manipulable means for unlatching said hammer to release the same for movement to fastener driving position; said hammer elevating means including an element adapted for connection to a flexible drive shaft.

14. A portable article gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative and manuall controllable article gripping and nailing mechanism all carried by said support, said mechanism comprising article gripping means, manually operable means for actuating said gripping means, a hammer to drive a fastener into the gripped article, a continuously operable motor operated means for elevating said hammer, means for latching the hammer in an elevated position, and manually manipulable means for unlatching said hammer to release the same for movement to fastener driving position, said continuously operable motor operated means including an element adapted for connection to a flexible drive shaft.

15. A portable article gripping and nailing device comprising a portable support adapted to be carried and manipulated by one hand of an operative and manually controllable article gripping and nailing mechanism all car.- ried by said support, said mechanism comprising article gripping means, manually operable means for operating said gripping means, a hammer to drive a fastener into the gripped article, means for elevating said hammer and for latching the same in anelevated position, manually operable means for unlatching said hammer to releasethe same for movement to fastener driving position, and means preventing release of said hammer until said gripping means is moved to gripping condition.

l6. A portable article supporting and nailing device comprising a portable casing, a handle for said casingand manually controllable article gripping and nailing mechanism all carried by said casing, said mechanism comprising a stationary article gripping jaw forming the bottom wall of said casing and forming the base support for said portable article supporting and nailing device, a movable article gripping jaw within the casing, manually operable means having a part arranged to be gripped with said handle by the operative for actuating said movable jaw, a driving means movably mounted withinsaid casing and arranged to drive a fastener into thegripped article, and manually controllable means having a trip element arranged exterior to said casing for controlling the operation of said driving means.

17. A portable article supporting and nailing device comprising a casing and manually controllable article gripping and nailing mechanism all carried by said casing, said mechanism comprising a stationary article gripping jaw forming the bottom wall of said casing and forming the base support for said portable article supporting and nailing de vice, a movablefarticle gripping jaw within 1 movable jaw, a hammer movably mounted within said casing and arranged to drlve a fastener into the gripped article, and manually controllable means having a trip element arranged exterior to said casing for control- A, ling the operation of said hammer.

18. A portable gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative and manually controllable article gripping and nailing mechanism all carried by said support, said mechanism comprising an article gripping means, manually operable means for actuating said gripping means, a hammer to drive a fastener into the gripped article, continuously operable motor operated means for elevating said hammer when the same is in a dropped position, means for holding said hammer in elevated position, and manually manipulable means for releasing said hammer for movement to its dropped or fastener driving position.

19. A portable gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative and manually controllable article gripping and nailing mechanism all carried bysaid support, said mechanism comprising an article gripping means, manually operable means for actuating said gripping means, a spring controlled hammer to drive a fastener into the gripped article, continuously operable motor operated means for elevating said hammer when the same is in a dropped position, means for latching said hammer in elevated position and manually manipulable means for optionally releasing said hammer for movement to its dropped or fastener driving position.

20. A portable gripping and nailing device comprising, a portable support adapted to be carried about and manipulated by an operative and manually controllable article gripping and nailing mechanism allcarried by said support, said mechanism comprising an article gripping means, manually operable means for actuating said gripping means, a driving means to drive a fastener into the gripped article, continuously operable motor operated means for restoring said driving means to a condition ready for a driving operation, and manually manipulable means for releasing said driving'means for movement to its fastener driving position.

21. Aportable article gripping and nailing device comprising a portable casing adapted to be carried about and manipulated by an operative, an article gripping means includ-' ing two parallel jaws, one movable relatively to the other, a manually controllable nailing mechanism carried by said casing, said mechanism comprising a hammer movable within the casing, means for elevating the said hammer, means for latching the hammer 1n an ele-f vated position, and manually manipulable means for unlatching said hammer to release the same for movement to a fastener driving position, said hammer being movable over the gripping means in position to drive a fastener through both jaws of the gripping means;

22. A portable article gripping and'nailing device comprising a portable casing adapted to be carried about and manipulated by an operative, an article gripping means in: cluding two parallel jaws, one movable relatively to the other, a manually controllable nailing mechanism carried by said casing, said mechanism comprising a driving means movable within the casing, a motor for controlling the operation thereof, and manually manipulable means for said driving means, said driving means being movable over the gripping means in position to drive a fastener through both jaws of the gripping means.

23. An article gripping device comprising a support, a fixed jaw having a flat'bottom face forming the fixed base of said support, a movable jaw arranged above the fixed jaw and cooperatingtherewith, said jaws being adapted to grip an article and stretch the same in a given plane, and means for operating said'jaws comprising manually manipulable elements movable relatively to each other in a direction parallel to said plane.

24. An article gripping device comprising a casing, a fixed jaw forming the bottom wall of said casing and'forming an extended base support for said gripping device, a movable jaw within the casing arranged above the fixed jaw cooperating therewith, said jaws beingadapted to grip an article, and means for operating said jaws comprising manually manipulable elements movable relatively to each other by contraction of the hand of the operator and ina direction substantially normal to the direction of movement of said movable jaw.

25. An article gripping and nailing device comprising a support, nailing mechanism carried by said support, a fixed jaw having a bottom face forming the fixed base of said support, a movable jaw arranged above the fixed jaw cooperating therewith, said jaws being adapted to grip an article and stretch the same in a given plane, and means for operating said jaws comprising manually manipulable elements movable relatively to each other in a'direction parallel to said plane.

'26. In a device of the class described, a hammer, means to lift the hammer, means to cause the hammer to deliver a driving blow, a spring-pressed latch to hold the hammer in the raised post-ion, and a thumb lever to which said latch is pivoted. v

271 In a device-of the class described, a hammer, means to lift the hammer, means to cause the hammer to deliver a driving blow, a spring-pressed latch to hold the hammer in the raised position, and a thumb lever to which said latch is pivoted; together With means to prevent undue movement of said latch on the thumb lever.

SAMUEL FRIEDMAN. 

